It depends on the nature of the failure, and whether we were able to image it. If not, you can manually adjust the Tach and Hobbs time in the setup menu. If you happen to have a setting file backup, you can look in that to get a recent number. Note that the Hobbs and Tach time are not imported when you load settings files though to avoid overwriting your timers with older information. Also, know that settings files backups are automatically generated and stored in a subfolder of your USB memory stick when you update your software.
The “old” display is still working after the uncommanded reboot, so I can get the Tach time from it. Just wasn’t sure I could enter it in Set up, but apparently I can. You mention Hobbs. Where can I find the Hobbs time?